Phase-Engineering-Driven Enhanced Electronic and Optoelectronic Performance of Multilayer In2Se3 Nanosheets.

Here, we report electronic and optoelectronic performance of multilayer In2Se3 are effectively regulated by phase engineering. The electron mobility is increased to 22.8 cm2 V-1 s-1 for β-In2Se3 FETs, which is 18 times higher than 1.26 cm2 V-1 s-1 of α-In2Se3 FETs. The enhanced electronic performance is attributed to larger carrier sheet density and lower contact resistance. Multilayer β-In2Se3 photodetector exhibits an ultrahigh responsivity of 8.8 × 104 A/W under 800 nm illumination, which is 574 times larger than 154.4 A/W of α-In2Se3 photodetector. Our results demonstrate phase-engineering is a valid way to tune and further optimize electronic and optoelectronic performance of multilayer In2Se3 nanodevices.